Apparatus and method for spatial atomic layer deposition

ABSTRACT

A semiconductor fabrication apparatus includes a processing chamber; a wafer stage configured in the processing chamber; and a chemical delivery mechanism configured in the processing chamber to provide a chemical to a reaction zone in the processing chamber. The chemical delivery mechanism includes an edge chemical injector, a first radial chemical injector, and a second radial chemical injector configured on three sides of the reaction zone.

PRIORITY

This is a continuation of U.S. patent application Ser. No. 16/222,731,which is a continuation of U.S. patent application Ser. No. 15/876,445filed on Jan. 22, 2018 and issued as U.S. Pat. No. 10,161,039, which isa continuation of U.S. patent application Ser. No. 15/169,999 filed onJun. 1, 2016 and issued as U.S. Pat. No. 9,873,943, which claimsbenefits of U.S. Prov. Pat. App. No. 62/267,793 filed on Dec. 15, 2015,the entire disclosure of which is herein incorporated by reference.

BACKGROUND

The semiconductor integrated circuit (IC) industry has experiencedexponential growth. Technological advances in IC materials and designhave produced generations of ICs where each generation has smaller andmore complex circuits than the previous generation. In the course of ICevolution, functional density (i.e., the number of interconnecteddevices per chip area) has generally increased while geometry size(i.e., the smallest component or line that can be created using afabrication process) has decreased. This scaling down process generallyprovides benefits by increasing production efficiency and loweringassociated costs. Such scaling down has also increased the complexity ofprocessing and manufacturing ICs and, for these advances to be realized,similar developments in IC processing and manufacturing are needed. Inone example, an atomic layer deposition process is utilized to from athin film. The atomic layer deposition technique deposits a thin filmwith a controlled deposition but has disadvantages of low depositionrate and decreased fabrication throughput. A spatial atomic layerdeposition is proposed to deposition a thin film with a controlleddeposition and improved deposition rate. However, available spatialatomic deposition has other issues, such as degraded film uniformity anddegraded film quality. Accordingly, it would be desirable to provide aspatial atomic layer deposition and a method of utilizing thereof absentthe disadvantages discussed above.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isemphasized that, in accordance with the standard practice in theindustry, various features are not drawn to scale. In fact, thedimensions of the various features may be arbitrarily increased orreduced for clarity of discussions.

FIG. 1 is a schematic and sectional view of a spatial atomic layerdeposition (SALD) module constructed in accordance with someembodiments.

FIGS. 2, 3, 4, 6, 7 and 8 are schematic and top views of a SALD modulein FIG. 1, constructed in accordance with some embodiments.

FIG. 5A is a schematic view of a chemical injector of the SALD module inFIG. 1, constructed in accordance with some embodiments.

FIG. 5B is a schematic view of a chemical injector of the SALD module inFIG. 1, constructed in accordance with some embodiments.

FIG. 9 is a block diagram of a SALD system having a SALD module of FIG.1, constructed in accordance with some embodiments.

FIG. 10 is a flowchart of a method utilizing the SALD system of FIG. 10,constructed in accordance with some embodiments.

DETAILED DESCRIPTION

It is to be understood that the following disclosure provides manydifferent embodiments, or examples, for implementing different featuresof various embodiments. Specific examples of components and arrangementsare described below to simplify the present disclosure. These are, ofcourse, merely examples and are not intended to be limiting. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. For example, if the device in the figures is turned over,elements described as being “below” or “beneath” other elements orfeatures would then be oriented “above” the other elements or features.Thus, the exemplary term “below” can encompass both an orientation ofabove and below. The apparatus may be otherwise oriented (rotated 90degrees or at other orientations) and the spatially relative descriptorsused herein may likewise be interpreted accordingly.

FIG. 1 illustrates a schematic and sectional view of a spatial atomiclayer deposition (SALD) module 100 in accordance with some embodiments.FIG. 2 is a top view of the SALD module 100, in portion, in accordancewith some embodiments. The SALD module 100 includes a processing chamber102. The processing chamber 102 includes an upper portion 102A and alower portion 102B integrated together, defining an enclosed space 104between the upper and lower portions. The SALD module 100 includes asubstrate stage 106 designed to secure one or more semiconductorsubstrate 108, such as six semiconductor substrates in one example. Insome examples, the substrate stage 106 may include a vacuum chuck tosecure the semiconductor wafer(s) 108. The substrate stage 106 furtherincludes a mechanism to rotate around a center axis 110, which isperpendicular to the semiconductor substrate (s) 108 secured thereon andpasses the center of the substrate stage 106. In some examples, thesubstrate stage 106 includes a rotation structure and a motor integratedto enable the rotation of the substrate stage 106. The semiconductorsubstrate(s) 108 secured on the substrate stage 106 moves along with thesubstrate stage 108 when the substrate stage 106 rotates.

In some embodiments, a semiconductor substrate 108 is a silicon wafer.In some embodiments, the semiconductor substrate 104 may include anelementary semiconductor, such as germanium in a crystalline structure;a compound semiconductor, such as silicon germanium, silicon carbide,gallium arsenic, gallium phosphide, indium phosphide, indium arsenide,and/or indium antimonide; or combinations thereof. In furtherance of theembodiments, those semiconductor material films may be epitaxially grownon the silicon wafer. In some other embodiments, the substrate 104 maybe a semiconductor wafer of a different material (such as siliconcarbide) or a substrate of some other material (such as a glasssubstrate).

The semiconductor wafer 108 has a front surface 108A and a backsidesurface 108B opposing from each other. One or more integrated circuitsare formed, partially formed, or to-be formed on the front surface 108Aof the semiconductor wafer 108. Therefore, the front surface 108A of thesemiconductor wafer 108 may include a patterned material layer or amaterial layer to be patterned. For examples, the front surface 108A mayinclude various isolation features (such as shallow trench isolationfeatures), various doped features (such as doped wells, or doped sourceand drain features), various devices (such as transistors), variousconductive features (such as contacts, metal lines and/or vias of aninterconnection structure), packaging material layers (such as bondingpads and/or a passivation layer), or a combination thereof. On acompletely fabricated semiconductor wafer, all above material layers andpatterns may be present on the front surface 108A of the semiconductorwafer 108. In the present example, the semiconductor wafer 108 is stillin the fabrication, a subset of the above material layers may be formedon the front surface 108A. The axis 110 is perpendicular to the topsurface 108A and the backside surface 108B of the semiconductor wafer108 secured on the substrate stage 106 or the front surface of thesubstrate stage 106. Even though the top surface 108A of the wafer maybe patterned and has a topographical profile, globally it is flat andparallel with the backside surface 108B.

FIG. 3 is a schematic and top view of the SALD module 100, in portion.The processing chamber 102 is further illustrated in FIG. 3. The SALDmodule 100 includes various features designed and configured to definevarious reaction zones. Thus, each wafer 108 secured on the substratestage 106 passes through various reaction zones and completes onereaction cycle when the substrate stage 106 rotates one circle. In someembodiments, the processing chamber 102 has a round shape in the topview and has a radius greater than the diameter of the wafer 108. Insome examples, the radius of the processing chamber 102 ranges between70 cm and 80 cm.

FIG. 4 is a schematic and top view of the SALD module 100 in portion,constructed in accordance with some embodiments. The SALD module 100includes a first chemical delivery mechanism 112 to provide a firstchemical to the first reaction zone 114, also referred to as precursorabsorption area. In some embodiments, the first chemical deliverymechanism 112 includes a top spray head configured on the upper portion102A of the processing chamber to deliver the first chemical toward thesubstrate stage 106 within the first reaction zone 114. In someembodiments, the top spray head is configured such that the firstchemical is delivered to the wafer 108 in a direction perpendicular tothe front surface 108A of the wafer 108 secured on the substrate stage106. In some examples for illustration, the first chemical includesdichlorosilane (SiH₂Cl₂ or DCS); hexachlorodisilane (Si₂Cl₆ or HCD);Bis(TertiaryButylAmino)Silane (C₈H₂₂N₂Si or BTBAS); trimethylaluminium(Al₂(CH₃)₆ or TMA), or other suitable chemicals, depending on the filmto be formed.

Other features are configured to further maintain the first reactionzone 114. In some embodiments, air edge mechanisms 116 are configured onboth sides of the first reaction zone 114 to constrain the firstchemical from diffusion and isolate the first reaction zone from otherreaction zones. The air edge mechanisms 116 are coupled to an inert gas(such as nitrogen or argon) source and provide the inert gas, forminggas walls to maintain and isolate the first reaction zone 114. When thewafer 108 is in the first reaction zone 114, the first chemical isdeposited (or adsorbed) on the front surface 108A of the wafer 108.

The SALD module 100 includes a second chemical delivery mechanism toprovide a second chemical to the second reaction zone 120, also referredto as reaction treatment area. In the present embodiment, the secondchemical delivery mechanism includes an edge chemical injector 122configured on the edge of the processing chamber 102, and furtherincludes a radial chemical injector 124 configured on a differentdirection, particularly along the radial direction on one side of thesecond reaction zone 120. Both the edge and radial chemical injectors(122 and 124) are elongated and the length dimensions are properlyoriented. Here the edge of the processing chamber 102 refers to theperimeter of the processing chamber 102 relative to the radialdirection. The radial direction refers to a direction from the edge tothe center 110 of the processing chamber. The radial chemical injector124 may be oriented along a direction slightly off the correspondingradial direction, such as providing freedom for fine tuning chemicaluniformity and deposition uniformity. For example, the length dimensionis oriented in a direction that has an angle of less than 15° with thecorresponding radial direction.

The radial chemical injector 124 substantially spans from the edge tothe center 110 of the processing chamber 102, such as spanning at least80% of the radius R or at least 90% of R in some embodiments.

The two chemical injectors are configured along two directions. Thesecond chemical is delivered to the second reaction zone 120 from twodirections by the injectors 122 and 124, respectively, as illustrated inFIG. 4.

The chemical injectors are thus configured to deliver the secondchemical to the second reaction zone 120. In some examples forillustration, the second chemical includes ammonia (NH₃), argon,nitrogen (N₂), hydrogen (H₂), helium (He), carbon dioxide (CO₂), oxygen(O₂), ozone (O₃), water (H₂O), hydrogen peroxide (H₂O₂), boronprecursor, or other suitable chemicals, depending the film to be formed.When the wafer 108 is in the second reaction zone 120, the secondchemical is delivered to the wafer and is further reacted with thepreviously adsorbed first chemical to form one atomic layer of the filmon the wafer, thus completing one cycle.

A chemical injector 126 is illustrated schematically in FIGS. 5A-B,constructed in accordance with some embodiments. The chemical injector126 is an example of the edge chemical injector 122 or the radialchemical injector 124. The chemical injector 126 includes a tube 128with one end 128A coupled to a chemical source for the second chemicaland another end 128B sealed. The tube 128 is designed to have aplurality of openings 130 with size, location and configuration toeffectively and uniformly inject the second chemical to the secondreaction zone 120. In some examples, the chemical injector 126 may havea length ranging between 300 mm and 600 mm. The openings 130 may have adiameter ranging between 0.2 mm and 1.2 mm. The number of the openings130 may range between 10 and 200.

Back to FIG. 4, the edge chemical injector 122 and the radial chemicalinjector 124 are integrated to the processing chamber 102 in aconfiguration so that both are higher than the wafer 108 on thesubstrate stage 106, such as higher than the wafer 108 with a relativeheight ranging between 2 mm and 10 mm. the SALD module 100 furtherincludes other isolation mechanism to maintain and separate variousreaction zones. For examples, various exhaust mechanisms 132, 134 and136, such as pumps, are configured at different locations of theprocessing chamber 102. Thus, the chemical diffused out of the targetedzone is pumped out and further diffusion to other regions is avoided. Inthe present example illustrated in FIG. 4, the exhaust mechanism 132 isconfigured on the edge of the processing chamber 102 in the firstreaction zone 114. In this case, the first chemical is delivered fromthe first chemical delivery mechanism 112 toward the wafer 108 withinthe first reaction zone 114 and is exhausted by the exhaust mechanism132 when it reaches to the edge of the first reaction zone 114. Theexhaust mechanisms 134 and 136 are configured on both sides of thesecond reaction zone 120 to exhaust the second chemical diffused out ofthe second reaction zone 120. The exhaust mechanisms purge the chemicalfrom previous reaction zone and prepare the wafer surface for the nextchemical. The exhaust mechanisms provide corresponding respective purgezones, such as purge zones 134Z and 136Z. The second reaction zone 120with thus configured chemical injectors has more uniform distribution ofthe second chemical, therefore more uniform chemical reaction rate,uniform film thickness and film quality.

The SALD module 100 may further include other features and otherreaction zones. FIG. 6 is a schematic and top view of the SALD module100 in accordance with some other embodiments. The SALD module 100further includes another radial chemical injector 138 configured onanother side of the second reaction zone 120. The radial chemicalinjector 138 is substantially similar to the chemical injector 124 interm of design, structure and dimensions. The radial chemical injector138 is also configured radially from the edge to the center 110 of theprocessing chamber 102 on the other side of the second reaction zone120. In the present embodiment, the radial chemical injectors 124 and138 are symmetrically configured on sides of the second reaction zone120, forming a central angle. Furthermore, the chemical injectors 122,124 and 138 are configured to enclose a triangle region as the secondreaction zone 120. In some embodiments, the edge chemical injector 122may be bent to match the sidewall of the processing chamber 102. Forexample, the edge chemical injector 122 is curved to an arc. Thus, thechemical injectors 122, 124 and 138 are configured to enclose a circularsector as the second reaction zone 120.

Thus, the three chemical injectors are configured in differentdirections and substantially enclose the second reaction zone 120,thereby maintaining a more uniform and high pressure of the secondchemical in the second reaction zone 120, with less diffusion to theoutside. Accordingly, the deposition rate and film quality are improved.

FIG. 7 is a schematic and top view of the SALD module 100 in accordancewith some other embodiments. The SALD module 100 further includes apre-reaction zone 140 for initial deposition of the second chemical. Thepre-reaction zone 140 may function in various perspectives, such asinitializing the chemical condition and further purge the firstchemical. In the pre-reaction zone 140, an edge chemical injector 142 isconfigured to provide the second chemical. The edge chemical injector142 may be similar to the edge chemical injector 122 (such as straightor curved in various embodiments). The edge chemical injector 142 has alength that may be different from (such as shorter than) that of theedge chemical injector 122, depending on the deposition efficiency,diffusion and purge effects of other regions. Since the second chemicalin the second reaction zone 120 is maintained with high and uniformdensity, and the diffusion of the second chemical is minimized, the edgechemical injector 122 may be designed with a shorter length, and theedge chemical injector 142 may be designed with a longer length. Thus,the second reaction zone 120 is enlarged, the rotation of the substratestage 102 can be increased and the throughput is also increased. Theedge chemical injector 140 is also connected to a chemical source forthe second chemical.

Still referring to FIG. 7, the SALD module 100 further includes apost-reaction zone 144 for post deposition of the second chemical. Thepost-reaction zone 144 may function in various perspectives, such asfinalizing and completing the chemical reaction in the second reactionzone 120. In the post-reaction zone 144, an edge chemical injector 146is configured to provide the second chemical. The edge chemical injector146 may be similar to other edge chemical injectors in structure, suchas same to the edge chemical injector 142 in terms of design, structureand dimensions. The edge chemical injector 146 is also connected to achemical source for the second chemical.

Still referring to FIG. 7, the SALD module 100 may further include otherisolation mechanisms, such as an exhaust mechanism 148 configuredbetween the pre-reaction zone 140 and the air edge mechanism 116 forfurther purge and isolation functions. In some examples, the SALD module100 may further include an exhaust mechanism 150 configured between thepost-reaction zone 144 and the air edge mechanism 116 for further purgeand isolation functions.

FIG. 8 is a schematic and top view of the SALD module 100 in accordancewith some other embodiments. The SALD module 100 further includes one ormore inner chemical injectors configured in or close to the center ofthe processing chamber and above the wafer 108 on the substrate stage106 to provide additional supply of the second chemical from differentdirections. In some examples, a first inner chemical injector 152 isconfigured in the center to provide the second chemical to thepost-reaction zone 144 in the direction opposite to the direction of thesecond chemical provided by the edge chemical injector 146. In someexample, the first inner chemical injector 152 is configured to face thechemical injector 146 and parallel with the edge chemical injector 146.The first inner chemical injector 152 may be similar to other chemicalinjectors in structure, such as same to the chemical injector 126 inFIGS. 5A-B but with different length and different design parameters,such as the length, the number of openings and/or the diameter of theopenings. The first inner chemical injector 152 is also connected to achemical source for the second chemical.

In some examples, a second inner chemical injector 154 is additionallyor alternatively configured in the center to provide the second chemicalto the pre-reaction zone 140 in the direction opposite to the directionof the second chemical provided by the chemical injector 142. In someexamples, the second inner chemical injector 154 is configured to facethe chemical injector 142 and parallel with the chemical injector 142.The second inner chemical injector 154 may be similar to the first innerchemical injector 152 in structure and sizes. The second inner chemicalinjector 154 is also connected to a chemical source for the secondchemical.

The SALD module 100 may further include other components, such as valveassociated with each chemical injector to control the respective gasflow and gas pressure in the respective reaction zone. Alternatively,all chemical injectors are connected to a same source of the secondchemical, and a master value is integrated to control the gas flows tothe all chemical injectors. In some examples, the second reaction zone120 may be controlled to have a partial chemical pressure up to 10 Torr.In some examples, the SALD module 100 includes another valve configuredbetween the first chemical delivery mechanism 112 and the first chemicalsource connected to the first chemical delivery mechanism 112 to controlthe flow rate and the gas pressure in the first reaction zone 114. Forexamples, the partially pressure of the first chemical in the firstreaction zone 114 is controlled to up to 2 Torr.

Various configurations and designs are provided above. Additionalcomponents and features may be further added to the SALD module 100.Other alternatives may be used without departure from the scope of thepresent disclosure. For examples, the radial chemical injector 124 (or138) may be configured along the radial direction toward the axis 110.Alternatively, the radial chemical injector 124 (or 138) may beconfigured along a direction away from the radial direction, such ashaving an angle of up to 15° with the corresponding radial direction. Inother examples, one or more heaters may be configured in the processingchamber 102, such as embedded in the substrate stage 106 for thermalheating effect during deposition. In some embodiments, the SALD module100 also includes dielectric plate configured in the processing chamberand connected to electric source for generating plasma in the secondreaction zone. For example, the radial chemical injector 124 is parallelwith the dielectric plate.

FIG. 9 is a block diagram of a SALD system 200 in accordance with someembodiments. The SALD system 200 includes one or more SALD modules 100integrated together in in a cluster tool. In an illustrative embodiment,the SALD system 200 includes two SALD modules 100 properly configuredand integrated.

The SALD system 200 includes one or more load port 202, through whichwafers are loaded and unloaded to the SALD system 200. In the presentembodiments, the wafers are loaded and unloaded in batches, by usingwafer containers, such as front opening unified pods (FOUPs).

The SALD system 200 may include a loader (or front end unit) 204 forholding, manipulating and transferring wafers. For examples, the loader204 includes one or more substrate stage 206 for holding and/ororienting one or more wafer. In other examples, the loader 204 includesone or more robot 208 for handling wafers, such as transferring wafersto the SALD modules 100 or to load lock chambers (or load lock units)210. The robot 208 is configured between the load port 202 and the loadlock chambers in a way for proper wafer transferring therebetween. Forexample, each wafer is transferred by the robot 208 from the load port202 or from the substrate stage 206 to one of load lock chambers, or istransferred back to the load port 202 by the robot 208. In someembodiments, the SALD system 200 may further include other components,such as one or more load lock chambers 210 configured and designed forvarious functions, such as pre-orientation and preconditioning. Thepreconditioning may include degassing, pre-heating or other functions.For examples, multiple load lock chambers 210 may designed andconfigured for various preconditioning functions, respectively. In someexamples, a wafer is oriented, degassed and/or pre-heated in one of theload lock chambers 210 to prepare the wafer for the SALD processing. TheSALD system 200 may be configured differently. For example, the loadlock chamber 120 in the middle may be used as a path to transfer thewafer(s). In other examples, the SALD system 200 further includes avacuum module integrated to provide vacuum conditions to respectiveregions, such SALD modules 100. The load ports 202, the loader 204 andthe load lock chambers 210 are collectively referred to as a load lockmodule 211.

The SALD system 200 may further include a transfer module 212 for wafertransfer between the SALD modules 100 and the load lock units 210. Insome embodiments, the transfer module 212 further includes one or morerobot 214 for wafer transferring. The transfer module 212 has openings(doors) 216 connected to the SALD modules 100, respectively.

FIG. 10 is a flowchart of a method 300 fabricating (particularly,depositing a thin film to by SALD technique) one or more semiconductorwafers 108, in accordance with some embodiments. The method 300 isimplemented in the SALD system 200 of FIG. 9. The method 300 isdescribed with reference to FIGS. 9, 10 and other figures.

The method 300 includes an operation 302 to load one or more wafers tothe SALD system 200 through the load ports 202. For example, wafers arein one or more batches, such as in FOUPs, are loaded to the SALD system200 through the load ports 202 in one or more steps, such as loading,degassing, pre-heating, orienting or a subset thereof.

The method 300 includes operation 304 to transfer one or more wafer toone of the SALD module 100 by the robot 214 through the opening 216. Forexample, the robot 214 sequentially transfers 6 wafers to each of theSALD modules 100. In other examples, the transfer module 212 may includetwo or more robots 214 to simultaneously transfer wafers to respectiveSALD modules 100. Specifically, in the present embodiment, six wafers108 are transferred to the substrate stage 106 of the corresponding SALDmodule 100 in a configuration that the front surface 108A faces upward,as illustrated in FIG. 1.

The method 300 proceeds to an operation 306 to perform a depositionprocess to the wafer(s) 108 in one of the SALD modules 100. Theoperation 306 and following operations are described with one SALDmodule and one wafer. However, as described above, the multiple wafers(such as 6 wafers) may be processed in one of multiple SALD modules 100and the multiple SALD modules 100 may work in parallel. In the presentembodiment, a thin film is deposited on the front surface 108A of eachwafer 108 during the operation 306.

During the deposition process, various components and units of the SALDsystem 200 work collectively and synergistically. Accordingly, theoperation 306 includes various sub-operations. Especially, the operation306 includes a sub-operation 306A to deposit a first chemical; and asub-operation 306B to deposit second chemical.

The operation 306 may further include other sub-operations, such asrotating the substrate stage 106. In the present embodiments of theoperation 306, the substrate stage 106 secures the wafer 108 and rotatesthe wafer around the axis 110, such as in a clockwise mode. Thissub-operation lasts through the deposition process in the operation 306.Each wafer 108 will sequentially pass each zone, such as the firstreaction zone 114 and the second reaction zone 120. In other examples,each wafer 108 will sequentially pass the first reaction zone 114, thepre-reaction zone 140, the second reaction zone 120, and thepost-reaction zone 144. Additionally, the wafer 108 will pass variousisolation regions (such as air edges associated with the respective airedge mechanisms 116 and the purge regions associated with the respectiveexhaust mechanisms respectively) from one reaction zone to anotherreaction zone. As an example for illustration, in the first reactionzone 114, the first chemical is delivered to the wafer 108 and adsorbedto the front surface 108A of the wafer 108. In the second reaction zone120, the second chemical is delivered to the wafer 108 and reacted withthe first chemical adsorbed on the front surface 108A, thereby formingan atomic layer on the front surface 108A of the wafer 108. One rotationcircle of the substrate stage 106 completes one cycle of the depositionprocess. One cycle forms one atomic layer. The operation 306 maycontinue as many cycles as needed to form the thin film with desiredthickness. Particularly, when the wafer 108 is in the second reactionzone 120, with the side chemical injector 122 and the radial chemicalinjector 124 (or additionally the radial chemical injector 138), thesecond chemical delivered to the second reaction zone 120 has a moreuniform distribution and a high density, therefore increasing thedeposition rate and improving the deposition quality. Since the secondchemical is substantially maintained and controlled inside the secondreaction zone 120, the purge zones and purge times may be substantiallyreduced, therefore increasing the throughput and decreasing themanufacturing cost.

After the completion of the deposition process to the wafer 108 in theSALD modules 100 by the operation 306, the method 300 proceeds to anoperation 308 to transfer the wafer 108 to the load lock chamber(s) 210by the robot 214. This operation is similar to the operation 304 but itis reversed. For example, the multiple wafers are transferred to theload lock chambers 210 from the SALD modules 100, sequentially or inparallel by multiple robots 214.

The method 300 may further include an operation 310 to unload the wafersfrom the SALD system 200 through the load port 202. The method 300 mayinclude other operations, before, during or after the operationsdescribed above. For example, after the operation 310, the wafers may betransferred to other fabrication tools for following fabrications, suchas lithography patterning process.

The SALD system 200 and the method 300 may have other embodiments, oralternatives. For examples, even though the method 300 describes aprocedure to form a thin film on a wafer by SALD technique, the SALDsystem and the method utilizing the same may be used to form variousthin films, such as gate dielectric layer, a gate electrode layer, acapping layer, a barrier layer, an etch stop layer or a dielectric layerfor a capacitor.

The present disclosure provides a SALD system and a method utilizing thesame. By utilizing the disclosed SALD system, the SALD deposition rateand quality are improved. The SALD system includes a second reactionzone configured with two or three chemical injectors oriented along theedge and the radial directions (or proximate radial directions) of thesubstrate stage.

The embodiments of the present disclosure offer advantages over existingart, though it is understood that other embodiments may offer differentadvantages, not all advantages are necessarily discussed herein, andthat no particular advantage is required for all embodiments. Variousadvantages may present in some embodiments. By utilizing the disclosedSALD system and the method, the deposition rate and film quality areimproved. Other advantages may include less purge time, lessmanufacturing cost and higher manufacturing throughput.

Thus, the present disclosure provides a semiconductor fabricationapparatus in accordance with one embodiment. The apparatus includes aprocessing chamber; a wafer stage configured in the processing chamber,the wafer stage is operable to secure and rotate a plurality of wafersaround an axis; a first chemical delivery mechanism configured in theprocessing chamber to provide a first chemical to a first reaction zonein the processing chamber; and a second chemical delivery mechanismconfigured in the processing chamber to provide a second chemical to asecond reaction zone in the processing chamber. The second chemicaldelivery mechanism includes an edge chemical injector and a first radialchemical injector.

The present disclosure provides a semiconductor fabrication system inaccordance with one embodiment. The semiconductor fabrication systemincludes a load lock module to load and unload plurality of wafers; atransfer module integrated with the load lock module; and a plurality ofspatial atomic layer deposition (SALD) modules integrated with thetransfer modules. Each SALD module includes a processing chamber; awafer stage configured in the processing chamber, the wafer stage isoperable to secure and rotate the plurality of wafers around an axis; afirst chemical delivery mechanism configured in the processing chamberto provide a first chemical to a first reaction zone in the processingchamber; and a second chemical delivery mechanism configured in theprocessing chamber to provide a second chemical to a second reactionzone in the processing chamber. The second chemical delivery mechanismincludes an edge chemical injector and a first radial chemical injector.

The present disclosure provides a method in accordance with oneembodiment. The method includes loading a plurality of wafers to aspatial atomic layer deposition (SALD) module; performing a depositionprocess to the plurality of wafers in the SALD module; and thereafter,unloading the plurality wafers from the SALD module. The SALD moduleincludes a processing chamber; a wafer stage configured in theprocessing chamber, the wafer stage is operable to secure and rotate theplurality of wafers around an axis; a first chemical delivery mechanismconfigured in the processing chamber to provide a first chemical to afirst reaction zone in the processing chamber; and a second chemicaldelivery mechanism configured in the processing chamber to provide asecond chemical to a second reaction zone in the processing chamber. Thesecond chemical delivery mechanism includes an edge chemical injectorand a first radial chemical injector.

The foregoing has outlined features of several embodiments. Thoseskilled in the art should appreciate that they may readily use thepresent disclosure as a basis for designing or modifying other processesand structures for carrying out the same purposes and/or achieving thesame advantages of the embodiments introduced herein. Those skilled inthe art should also realize that such equivalent constructions do notdepart from the spirit and scope of the present disclosure, and thatthey may make various changes, substitutions and alterations hereinwithout departing from the spirit and scope of the present disclosure.

What is claimed is:
 1. A semiconductor fabrication apparatus,comprising: a processing chamber; a wafer stage configured in theprocessing chamber; and a chemical delivery mechanism configured in theprocessing chamber to provide a chemical to a reaction zone in theprocessing chamber, wherein the chemical delivery mechanism includes anedge chemical injector, a first radial chemical injector, and a secondradial chemical injector configured on three sides of the reaction zone.2. The semiconductor fabrication apparatus of claim 1, furthercomprising: two exhaust mechanisms configured in the processing chamberto provide first and second purge zones outside of the reaction zone. 3.The semiconductor fabrication apparatus of claim 2, wherein each of thetwo exhaust mechanisms is configured at an edge of the processingchamber.
 4. The semiconductor fabrication apparatus of claim 1, furthercomprising: a pre-reaction edge chemical injector configured in theprocessing chamber to provide the chemical to a pre-reaction zone; and apost-reaction edge chemical injector configured in the processingchamber to provide the chemical to a post-reaction zone.
 5. Thesemiconductor fabrication apparatus of claim 4, wherein the reactionzone is between the pre-reaction zone and the post-reaction zone, andwherein the wafer stage is operable to rotate a wafer through thepre-reaction zone, the reaction zone, and the post-reaction zone insequence.
 6. The semiconductor fabrication apparatus of claim 4, furthercomprising: a first inner chemical injector configured close to a centerof the processing chamber and configured to face the pre-reaction edgechemical injector; and a second inner chemical injector configured closeto the center of the processing chamber and configured to face thepost-reaction edge chemical injector.
 7. The semiconductor fabricationapparatus of claim 1, wherein the edge chemical injector is straightsuch that the edge chemical injector, the first radial chemicalinjector, and the second radial chemical injector enclose a triangularregion as the reaction zone.
 8. The semiconductor fabrication apparatusof claim 1, wherein the edge chemical injector is curved such that theedge chemical injector, the first radial chemical injector, and thesecond radial chemical injector enclose a circular sector as thereaction zone.
 9. The semiconductor fabrication apparatus of claim 1,wherein the chemical is selected from the group consisting of ammonia(NH₃), argon, nitrogen (N₂), hydrogen (H₂), helium (He), carbon dioxide(CO₂), oxygen (O₂), ozone (O₃), water (H₂O), hydrogen peroxide (H₂O₂),and boron precursor.
 10. The semiconductor fabrication apparatus ofclaim 1, wherein the chemical delivery mechanism is a second chemicaldelivery mechanism and the chemical is a second chemical, furthercomprising: a first chemical delivery mechanism configured in theprocessing chamber, wherein the first chemical delivery mechanismprovides a first chemical different from the second chemical to a regionoutside of the reaction zone.
 11. A method for semiconductorfabrication, comprising: transporting a wafer to a first reaction zonein a processing chamber; depositing a first chemical to the waferthrough a first chemical delivery mechanism configured in the firstreaction zone; transporting the wafer to a pre-reaction zone in theprocessing chamber; depositing a second chemical to the wafer through asecond chemical delivery mechanism configured in the pre-reaction zone,wherein the second chemical is different from the first chemical; afterthe depositing of the second chemical in the pre-reaction zone,transporting the wafer to a second reaction zone in the processingchamber; and depositing the second chemical to the wafer through a thirdchemical delivery mechanism configured in the second reaction zone. 12.The method of claim 11, wherein the second chemical is delivered to thepre-reaction zone along an edge of the processing chamber.
 13. Themethod of claim 11, wherein the second chemical is delivered to thepre-reaction zone from a center of the processing chamber.
 14. Themethod of claim 11, wherein the second chemical is deliver to the secondreaction zone along an edge and a radical direction of the processingchamber.
 15. The method of claim 11, further comprising: transportingthe wafer to a post-reaction zone in the processing chamber; anddepositing the second chemical to the wafer through a fourth chemicaldelivery mechanism configured in the post-reaction zone.
 16. The methodof claim 11, further comprising: transporting the wafer to pass by anexhaust mechanism configured between the first reaction zone and thepre-reaction zone.
 17. A method for semiconductor fabrication,comprising: loading a wafer into a processing chamber, the processingchamber including a reaction zone; securing the wafer on a wafer stagein the processing chamber; rotating the wafer stage to pass the waferthrough the reaction zone; and delivering a chemical towards a topsurface of the wafer while the wafer is passing through the reactionzone, the chemical being delivered to the reaction zone along at least aperimeter edge and a first radial edge of the reaction zone.
 18. Themethod of claim 17, wherein the chemical is also delivered to thereaction zone along a second radial edge of the reaction zone.
 19. Themethod of claim 17, wherein the chemical delivered along the firstradial edge of the reaction zone spans at least 80% of a radius of theprocessing chamber.
 20. The method of claim 17, further comprising:rotating the wafer stage to pass the wafer through a post-reaction zone;and delivering the chemical towards the top surface of the wafer whilethe wafer is passing through the post-reaction zone.